Serena rolls to victory at Aussie Open

MELBOURNE, Australia -- Serena Williams was only two points from her 500th career match win when she tumbled to the court in the second round of the Australian Open.

It's OK, she thought, it's the good ankle. After sitting and watching Barbora Zahlavova Strycova's shot float out to end the penultimate rally, Williams got up and whipped a backhand winner down the line on match point to move into the third round with a 6-0, 6-4 victory earlier today.

It improved her career record to 500-104 in tour matches and it was her 16th consecutive match win at Melbourne Park, where she has won five of her 13 Grand Slam titles.

"It's totally fine. It was my good ankle, so I'm good," she said, playing down concern that the fall had aggravated the left ankle sprain which hampered her preparation for the season's first major. "There was no extra pain. I twisted it. But it's all taped up, so the tape really, really helped."

She'd earlier put it down to just having "wobbly ankles."

"I wasn't meant to be a ballerina or anything," she said in a post-match TV interview. Williams won the Australian Open in 2009 and 2010, but didn't get to defend her title in 2011 because she was injured.

Top-ranked Novak Djokovic gained a 6-3, 6-2, 6-1 win over Santiago Giraldo of Colombia, his 16th in a row in majors as he stayed on track to become only the fifth man in the Open era to win three consecutive Grand Slam singles tournaments.

Sixth-seeded Jo-Wilfried Tsonga, who lost the 2008 Australian final to Djokovic, advanced 7-5, 6-4, 6-4 over Ricardo Mello of Brazil, while No. 5 David Ferrer struggled early against American Ryan Sweeting before coming back to win 6-7 (4), 6-2, 3-6, 6-2, 6-3

On the women's side, No. 2 Petra Kvitova, the reigning Wimbledon champ, scraped into the third round with a nervous 6-2, 2-6, 6-4 win over Carla Suarez Navarro.

Maria Sharapova, one of the three former champions in the women's draw, reached the third round with a 6-0, 6-1 rout of U.S. qualifier Jamie Hampton in 64 minutes.

American John Isner, seeded 16th, won a 4-hour, 41-minute marathon, including a 99-minute fifth set, over former Wimbledon finalist David Nalbandian. Isner had 43 aces in his 4-6, 6-3, 2-6, 7-6 (5), 10-8 win.

Nalbandian had several run-ins with the chair umpire during the often tense match. The Argentinian was enraged when a tournament official refused to overrule the chair umpire's decision to decline a review of a line call late in the fifth.